Distributing valve



March 26, 1935. M' F GUTERMUTH 1,995,885

DISTRIBUTING VALVE Original Filed Jan. 30, 1923 y@ \f1 25? ff [621), f4

Patented Mar. 2s, 1935 UNITED STATES Original application January 30,1923, Serial No.

615,957. Divided and this application February 6, 1929, Serial No.337,787. In Germany April 4, 1923 My invention relates to distributingvalves, and more particularly to distributing valves for controlling theflow of motive fluid to a motor.

My invention resides in valve structure of the reciprocating or slidingtype comprising a valve seat having a restricted opening therein, and aslide valve operating on said seat and adapted to form with said openinga substantially stream line passage for permitting flow of a gaseousfluid, as steam, air or gas, therethrough at its critical velocity; andmore particularly my invention resides in distributing valve structureof the piston type, wherein a restricted valve opening or portcommunicates with an annular diffuser passage for permitting maximumflow of fluid for a given stroke of the valve and accordingly limitingthe size and mass of the valve.

My invention further resides Vin apparatus of the character hereinafterdescribed and claimed.

In piston slide-valves of the type ordinarily used, the valve stroke maybe reduced only by increasing the circumference of the piston, i. e. byincreasing the diameter of the valve, or by the construction of multipleflow slots. as in the case of the so-called Penn slide valve, the valveconstruction being considerably involved and complicated insuch cases.

The main object oi my invention is to diminish to a considerable extentthe size and mass of distributing valves. particularly of the slide orpiston type, and to reduce their stroke or opening movement withoutincreasing the actual pressure loss yin the valve passage by more thanthe theoretical velocity head. 1

In distributing valves of previous construction, large losses haveoccurred due to throttling action at the valve openings. In my presentinvention, however, these losses are greatly diminished. and inaddition, the size and lift of the valve decreased to a theoreticalminimum by combining a substantially stream-line diffuser passage of acharacter hereinafter described with special valve structure. The valveand its cooperating valve seat are proportioned to form the beginning ofa diverging difluser passage, the valve passage being designed as astream line passage to permit flow of a motive fluid. as steam, forexample, therethrough at its critical velocity. The critical velocity ofsteam, for instance. ranges be- 50 tween 450 and 560 meters per second.

By such combination of a stream line diffuser passage with special valvestructure designed on the basis of the critical velocity of the motivefluid. it is obvious that the theoretical minimum valve lift or openingmay be attained. In ac- 9 Claims. (Cl. 251-75) cordance with suchdesign, the size and mass of the valve may also be reduced, therebyreducing both inertia of the movable valve structure, and leakage byreason of the smaller valve opening. By my simplified valve structure.the loss of pressure of the working substance during its admission intothe working-cylinder does not exceed the losses produced by smallvelocities of flow in ordinary distributing valves having relativelylarge dimensions.

For an illustration of some of the forms my invention may take,reference is had to the accompanying drawing, in which:

Fig. 1 is a view, partly in section, of one form of distributing valve.

Fig. 2 is a view, partly in section, of another form of distributingvalve. l

Fig. 3 is a sectional view on line 3--3 of valve structure shown in Fig.2.

Fig. 4 is a sectional view on line 4-4 of valve structure shown in Fig.2.

Referring to Fig. 1, a housing or supporting structure H comprises acylindrical bore extending therethrough and communicating at one endwith a steam passage S; A valve seat or bushing T is mounted withinhousing H, and comprises a hollow cylindrical member fitted within the/bore, and having an annular positioning shoulder t at one end thereoffor engaging a cooperatlng shoulder t1 of' housing H.

Valve seat T has an opening or port t2, preferably substantially annularin shape, extending through the wall thereof, and adapted to be incommunication with the steam passage S when the valve is open, and withan annular diverging passage D formed within the walls of housing Hexteriorly and concentrically of the valve seat.

The diverging passage D, hereinafter referred to as the diffuserpassage, communicates with an outlet passage O leading to a cylinderchamber. or equivalent.

Slidably mounted within valve seat T is a valve V of the piston type,having an operating member or stem M and a portion or extension V1diverging with respect to passage S. The diverging portion V1 is soshaped that when valve V is in its fully opened position as illustratedin Fig. 1, there will be a continuous uninterrupted substantially streamline passage comprising converging passage S1, a restricted passage orport t2 in the valve seat, and the diverging or diffuser passage D,interconnecting steam passage S and outlet O. To the end that a changein direction of flow of the motive fluid may be attained withoutincurring appreciable losses, the surface v1 of the piston body V1 isformed as a surface of revolution by a line so shaped that no change ofdirection in flow occurs at the place of passage of the steam or motivefluid from the admission space into the diffuser space, i. e. at porttz.

The cross-sectional area of the restricted portion of the diffuserpassage tn is of such dimensions, and the shape of the passage such thatilow of a gaseous uid such as steam, air or gas, will pass therethroughat the critical velocity of that particular uid when valve V is in itsopened position. The diffuser passage D gradually diverges or increasesin cross-sectional area as it extends from port t2, said port forming,together with the diffuser passage D, the diverging portion V1 of thevalve, and the wall of the valve seat, a continuous substantiallystreamline passage. The 'valve opening or port ta is opened or closed inaccordance with reciprocatory movement of valve V, the stroke of valveV, as well as its diameter, being reduced to a minimum by utilizing thecritical velocity of uid iiow.

The above described valve structure is adapted to be used in combinationwith uniiow cylinders having exhaust slots, the construction of uniflowcylinders being well known in the fluid motor art.

Another form of distributing valve embodying the above principles isillustrated in Fig. 2, wherein a housing'Hi, as in the previousinstance, comprises a circular bore extending therethrough. Acylindrical valve seat T1 is disposed within the bore, and comprises anannular positioning shoulder t: in engagement with shoulder t4 ofhousing H1. Valve seat T1 has a pair of substantially annular openingsor ports t5 and tu extending through the walls thereof, and incommunication with a steam passage S and an outlet passage Orespectively. Port te communicates by way of an annular passage orrecess h in the wall of housing Hi with outlet O.

A valve member V2 is seated within the cylindrical valve seat T1, andcomprises a piston-like member adapted for reciprocatory movement withrespect to its seat. Valve Vz comprises an operating member or stem M1extending longitudinally of the valve member and secured thereto as by ashoulder or collar m at one end of the valve and a securing nut m1threaded to the end of member M1 and engaging the other end of valve Vz.Comprised within valve V2 is a substantially annular stream linediverging passage D1, hereinafter referred to as the diiuser passage,and during open position of the valve, as illustrated in Fig. 2, extendsfrom the valve seat opening te (the cross-section of opening t5coinciding with the restricted portion of diffuser passage Dicommunicating therewith), to the valve seat opening te, which is ofconsiderably greater width than opening ts, and coincides with thewidest part of the diffuser passage communicating therewith.

In the type of valve illustrated in Fig. 2, the valve seat T1, as wellas a portion of valve V1, extends to the left appreciably beyond thebore referred to and into the steam passage S. Accordingly, that part ofthe valve and valve seat extending into the fresh steam passage willreceive heat therefrom, and consequenthr the steam, or equivalent motiveuid, will receive a certain amount of heat from the steam passage whilepassing through the first part of the diffuser passage D1, andaccordingly will enter the cylinder or working chamber at highertemperature.

As contrasted with the valve shown in Fig. 1, wherein the diffuserpassage in general is disposed exteriorly and circumferentially of thevalve V,

the diuser passage D1 in Fig. 2 is comprised substantially within valveVn, and co-operates with two valve ports of different size, defining therestricted and widest openings of the diffuser passage respectively.

It will be particularly noted that in the construction illustrated inFig. 2 wherein the diffuser passage is substantially comprised withinthe valve itself, the surrounding valve seat and housing may be smallerin diameter due to elimination of the diffuser passage therein.Accordingly, when valve Vz is of large diameter, as in the case of largeinstallations, incorporation of the diffuser passage within the valveproper effects considerable reduction in the mass and exteriordimensions of housing H1, as would otherwise be the case if housing H1had the diffuser passage incorporated therein.

Valve Vi is furthermore constructed so that it may control exhaust aswell as admission of the motive fluid. That is, when valve V2 has movedto the left so that the edge of surface vz has traversed port te, anexhaust passage is formed comprising port te and the diffuser passageformed by the surface v: of the valve and the inner wall of the valveseat. The annular exhaust diffuser opens into the exhaust passage O1.

As has been previously stated, the usual distributing valves for steam,air, and gas engines in general have the inherent disadvantage of largethrottling losses caused by the fact that the maximum eiiiciency of theactual openings of the valves are not realized. Although diiusers havebeen previously used in connection with Venturimeters and in theconstruction of section tubes for water turbines, etc., so far as I amaware, the use of a diffuser in connection with slide valves for steam,air or gas engines was not known prior to my invention. v

The advantages attained by combining a distributing valve of the abovedescribed type with a diffuser passage, as previously stated, includelimiting both the size and mass of the reciprocating member, as well aslimiting the valve controlling movement or stroke to a theoreticalminimum, from which it follows that the valve may complete its strokewithin a comparatively small interval of time.

In other words, for a given pressure of steam for example, and for agiven cross-sectional area of the valve opening, there will be maximumra of flow of the steam through the valve passage. It accordinglyfollows that where the critical velocity of the fluid is attained, thevalve opening or ports may be of the smallest theoretical size, and thestroke and diameter of the valve may be consequently reduced to aminimum, while at the same time high thermal efficiency is maintained.

By reducing the inertia of the valve and its stroke to a minimum, therewill be an increase in mechanical efficiency as well as a reduction ofthermal losses due to throttling, the last named losses beingconsiderable in the case where the valve moves through an appreciabledistance during its stroke.

As will be noted from the drawing, the valve in Fig. l completes itsstroke within the extent of movement represented by the width of porttz, and in Fig. 2 the total stroke is representative of the width ofport t5, and not port te which repv resents the widest portion of thediffuser passage. In the case where valve Vz controls both the admissionand exhaust of the motive fluid, the extent of movement of the exhauststroke is represented by the combined width of port te and that part ofthe valve between Di and v2.

It is to be understood that my invention is not limited to the specificforms hereinabove described, but may comprehend other forms embodyingthe above described principles and similar structure.

This application is a division of my copending application Serial No.615,957, filed January 30, 1923.

What I claim is:

l. A distributing valve for a gaseous fluid as steam, air or gascomprising, in combination with a substantially cylindrical valve seathaving a substantially annular opening therein, a pistonlike valvemember adapted to reciprocate within said cylindrical valve seat, saidmember having a surface adapted to form with said valve seat and thewall of the annular opening in the valve seat a portion of the wall of acontinuous substantially stream line fluid passage increasing incross-sectional area from said annular opening.

2. Distributing valve structure comprising a casing having a boretherethrough and a sub-- stantially annular passage communicatingtherewith, a substantially cylindrical valve seat disposed within saidbore and having a substantially annular opening communicating with saidpassage, and a piston-like valve member adapted to reciprocate withinsaid cylindrical seat, said valve member having a surface shaped to forma portion of the wall of a continuous fluid passage between said boreand said annular opening of progressively varying area. Y

3. A distributing valve comprising in combination with a housing havinga bore and an annular recess therein, and a cylindrical valve seatdisposed within said housing and having openings communicating with saidbore and recess, respectively of a piston-like member adapted forreciprocatory movement within said valve seat, said member having adiverging passage therein adapted to form with said valve seat openingsa substantially stream line diffuser passage extending from said bore tosaid annular recess.

4. Structure for controlling the flow of elastic fluid comprising, incombination, a cylindrical valve seat having an annular port therein, apiston-like valve member adapted to reciprocate within said valve seat,said valve member having a surface extending from adjacent the Ype-,riphery of said valve member and diminishing in diameter longitudinallythereof, to form with said valve seat a portion of the wall of asubstantially stream line passage of which said port in said valve seatis the portion having the least cross-sectional area normal to thedirection Yof flow through the passage, said valve member in itsmovement axially of said valve seat opening and closing said port insaid valve seat.

5. Structure for controlling the flow of elastic fluid comprising, incombination, a cylindrical valve seat having an annular port therein, apiston-like valve member adapted to reciprocate within said valve seat,said valve member having a surface extending from adjacent the peripheryof said valve member and diminishing in diameter longitudinally thereof,to form with said valve seat a portion of the wall of a substantiallystream line passage including said port in said valve seat and divergenttherefrom, said valve member in its movement axially of said valve seatopening and closing said port in said valve seat.

6. A distributing valve structure including a substantially cylindricalvalve seat having a substantially annular opening therein, asubstantially cylindrical valve'member disposed to reciprocate relativeto said valve seat to open and close the opening therein, said valvestructure including a substantially stream line fluid passage formed atleast in part by a surface of said reciprocating .valve member when inits open position and said annular opening and increasing incross-sectional area from said opening.

7. A distributing valve structure including a substantially cylindricalvalve seat having a substantially annular opening therein,` apiston-like valve member disposed to reciprocate within said valve seatto open and close the opening therein, said valve structure including afluid passage of progressively varying area and'formed at least in partby a surface of said reciprocating valve member when in its vopenposition and said annular opening, said annular opening constituting themost constricted portion of said passage.

casing havingl a bore therethrough and an annular passage communicatingtherewith, a substantially cylindrical valve seat disposed within saidbore and having a substantially annular opening interconnecting saidvpassage and' said bore, a substantially cylindrical v-alve memberdisposed to reciprocate relative to said valve seat to open and closethe'opening-therein, said valve structure including a substantiallystream line fluid passage between said bore and said annular passageformed atleast in part byel surface of said reciprocating valve memberwhen in its. open position and said annular o peningv and increasing incross-sectional area; from said opening.

9. A distributing valve structure including a substantially cylindricalvalve seat having a substantially annular opening therein, asubstantially cylindrical valve member disposed to reciprocate relativeto said valve seat to open. and close the opening therein, and asubstantially stream line diffuser passage formed insaid reciprocablevalve member and forming with vsaid annular opening a continuoussubstantiallyV stream line passage.

MAX F. GUTERMUTH.

8. A distributing valve structure comprising a`

